The disposal of infectious wastes, especially in a hospital environment, is a perennial problem. What is needed is an inexpensive, effective method of killing a myriad of infectious organisms over the period of use of a disposable container. What is available is an assortment of approaches which incompletely and imperfectly addresses this need. What is taught and offered in this application is a better solution to the needs of the marketplace.
One approach, already commercialized, uses a buffered solution of sodium pyrosulfite (sodium metabisulfite, Na.sub.2 S.sub.2 O.sub.5) to release sulfur dioxide as a vapor phase bactericide at a controlled rate so as to maintain its concentration in the container at 75-150 ppm over a period of several weeks, the concentration being sufficient to kill all bacteria in about 24 hours. C. M. Lucas and M. F. Mendes, J. Hyg. Camb., 84, 41 (1980); cf. U.S. Pat. No. 4,128,397. The use of a gas has the advantages of completely filling the container with a bactericide so that all surfaces are in contact with the disinfectant. Because of the high permeability of gases through many materials containing infectious microorganisms, disinfecting gases also may contact interior surfaces inaccessible to liquids, thereby acting more efficaciously.
Many gas phase disinfectants are known, including sulfur dioxide, glyoxal, iodine, chlorine, malondialdehyde, glutaraldehyde, methylene chloride, formaldehyde, and ammonia. It is not necessary that a gas phase disinfectant be a vapor at normal temperatures, but only that the material has a sufficiently high vapor pressure that its gas phase concentration at its intended temperature of use be sufficiently high to impart bactericidal properties. Recently Bovallius and Anas, Applied and Environmental Microbiology, 34, 129 (1977) have reported that glutaraldehyde is an effective gas phase surface disinfectant at a concentration between 15-20 mg/m.sup.3 for a broad variety of infectious microorganisms and bacterial spores. This latter observation is especially significant since spores generally are inherently difficult to kill.
The objective sought was a slow release, gas phase disinfectant. The evaluation of various available gas phase disinfectants pointed to aldehydes such as glutaraldehyde as being particularly effective and therefore are specially desirable disinfectants. The problem then became how to obtain a slow, controlled, and sustained release of gas phase aldehydes. Since aldehydes are susceptible to oxidative degradation a related problem was how to maintain the stability of an aldehyde during storage. Another but by no means unimportant consideration was to achieve such results at low cost, in a manner conducive to its use in a variety of operating environments, and to achieve such results efficiently.